Performance databases that can be referred to as numerical values play important roles in the research of music interpretation, the analysis of expressive performances, automatic transcription, and performance rendering technology.

The authors have promoted the creation and public release of the CrestMuse PEDB (Performance Expression DataBase), which is a performance expression database of more than two hundred virtuoso piano performances of classical music from the Baroque period through the early twentieth century, including music by Bach, Mozart, Beethoven and Chopin. The CrestMuse PEDB has been used by more than fifty research institutions around the world. It has especially contributed to research on performance rendering systems as training data.

Responding to the demand to increase the database, we have started a new three-year project to enhance the CrestMuse PEDB with a second edition that started in 2016. In the second edition, phrase information that pianists had in mind while playing the performance is included, in addition to the performance data that can be referred to as numerical values.